Safety throttle



Dec. 25 1923. 1,478,710

E. B. HARRIS SAFETY THROTTLE Filed Jan. 11. 1921 2 Sheets-Sheet 1 Dec. 25, 1923. 1,478,710

E. B. HARRIS SAFETY THROTTLE Filed Jan. 11. 1921 x 2 Sheets-Sheet 2 INVENTOR E. B HARRIS.

Patented Dec. 25, 1923.

srars EDWARD B. HARRIS, OF PORTLAND, OREGON.

SAFETY THROTTLE.

Application filed January 11, 1921. Serial No. 436,489.

To all whom it may concern:

. Be it known that I, EDWARD B. HARRIS, a citizen of the United States, residing at Portland, in the county of Multnomah and State of Oregon, have invented a new and useful Safety Throttle, of which the following is a specification.

My invention relates to improvements in safety throttles for steam engines, in which a trip valve stops the operation of the engine and sends the steam to a shock absorber.

The objects of my invention are to furnish an apparatus which -will' stop the engine instantly from any desired point and do it without any shock to the steam pipes or boilers.

Other objects and advantages will appear from the description given hereinafter.

I attain these objects with the mechanism illustrated in the accompanying drawings, in which Fig. I is an elevation of the entire .apparatus, the shock absorber being shown in section.

Fig. II is an elevation of Fig. I as seen from the line AA.

Fig. III shows some details of the tripping mechanismon a somewhat larger scale.

Fig. IV is an elevation of Fig. I along the line B-B.

Fig. V is a section of Fig. II along the line CC.

Fig. VI is a section through the vane chamber in Fig. I along the line I)D.

Similar numerals refer to similar parts throughout the several views.

The interior closing mechanism for the throttle valve 1 may be of any suitable construction, the one shown in the drawings is of the rotary disk type, with a crank 2 on the stem. As the steam from the main pipe 3 passes the ports 1 of the throttle valve, it enters a wedge shaped chamber 5 which forms a part of the valve housing and is most clearly illustrated in Fig. IV. From here the steam may either be directed to the engine (not shown) through the pipe. 6 or to the shock absorber 7 through the pipe 8. A vane 9 in the chamber 5 is capable of oscillating from one side to the other and of barring the steam from the pipe whose orifice becomes thereby covered The pivot for the vane 9 is designated by the numeral 10 and extends into the vane chamber 11 (Figs. V to VI) to carry therein another vane 12 diametrically opposite to the vane 9. At one side of the vane chamber there is a trip-valve 13 whose central bore 14:

communicates with the interior of the pipe engine.v The rotating or tripping of the trip valve is accomplished by a horizontal wire 18 (Fig. II) whose one end is attached to the vertical wire 19 while the other end may be led to any place in mill or factory from whence emergency stops may. be wanted. A pull at the Wire 18 will raise the lever 20 to the dotted position shown in Fig. III, and thereby release the pawl 21. The manner of supporting the lever at the pivotal point and returning it to its original position is immaterial. In the drawing this is done by a pin '22, attached to adjacent parts of the machine and the torsion spring 23 around'the pin. The'pawl 21 being released, drops in the direction of .the'dotted I line in Fig. III and since said pawl is firmly attached to the valve stem 24: of the trip valve, the valve itself must turn and permit the steam to enter the vane chamber. A torsion spring 25 around the valve stem makes the rotation quick and positive. The closing of pipe 6 has automatically opened the pipe 8 whereby the steam is sent into the shockabsorber 7. Here the steam expends its force by raising the spring piston 26. The latter having reached the limit of its travel knocks with its hook 27 against the catch 28 and thereby opens the valve 29. This sends the steam through the pipe 30 into the cylinder 31, raises the piston 32 (Fig. V) with its piston rod 33 and thereby closes the throttle valve 1. Removal of steam pressure from the shock absorber returns the spring piston 26 to its original position and the hook 27, by pressing against the catch 34 closes the valve 29. The ascent of the piston 32 bares the port 35 (Fig. V) in the cylinder 31, whereby the steam is enabled to enter through the pipe 36 the vane chamber 11 and to return vane 12, and therewith vane 9, to the original position. The closing motion of the crank 2 also returns the trip valve to its original position. This is accomplished by means of a link 37 between crank 2 and a pm 38 in the pawl 21. The

lower end of the link is slotted so that the engineer may open his throttle valve without hindrance, the pawl is thereby also enabled to trip when the next emergency arises. The full line 37 in Fig. III denotes the position of the link before tripping, the dotted line, after tripping. IVith all of the elements automatically restored to their original position, the engineer can now start his engine by turning the crank on the throttle valve down, and everything is ready for a new emergency The ports 39 in Fig. VI permit an escape of the steam pressure when the vane 12 has reached its extreme position either Way. Numeral 40: designates a ceiling, and numeral 41, a bracket for the support of the cylinder 31.

Having thus described my invention, it will be seen that my objects have been accomplished, and, though I have shown the preferred form of construction, I reserve to myself the right to make minor changes providing I do'not violate the spirit and principle of my invention. It is a simple matter to use the shock absorber as a brake on any suitable part of the engine, such use is therefore considered to fall within the scope of my invention.

1. In a safety throttle, a valve body having a steam inlet and a double steam outlet, a shock absorber communicating with one of said outlets, an auxiliary valve adapted to close either one of said outlets and normally barring the outlet to the shock absorber, and means to actuate the auxiliary valve, whereby steam is barred from the normally open outlet and sent to the shock absorber.

2. In a safety throttle, a valve body having a steam inlet and a double steam outlet, a shock absorber communicating with one of said outlets, an auxiliary valve capable of communicating with the other outlet, said auxiliary valve including a vane extending into the valve body and adapted to close either one of said outlets, and means to establish communication between the auxiliary valve and its respective steam outlet,iwhereby the vane in the valve body opens the way to the shock absorber and bars admision of steam to the auxiliary valve.

3. In a safety throttle, a valve body having a steam inlet and a double steam outlet, an individual valve for the steam inlet, an auxiliary valve adapted to close either one of said outlets, a trip valve capable of transmitting steam from one of said outlets to the auxiliary valve, a shock absorber attached to the other outlet, a cylinder having a piston cooperatively connected with the individual valve, and a connecting pipe between shock absorber and cylinder whereby steam entering the shock absorber operates said piston and actuates the individual valve.

Signed by me at Portland, Oregon, this 5th day of January, 1921.

EDWARD B. HARRIS. 

